[Mesa-dev] [PATCH 3/7] i965: Move fallback size assignment out of bufmgr

[Daniel Stone]

The bufmgr took a mandatory size argument, which would only be used if
the kernel size query failed, i.e. an older kernel. It didn't actually
check that the BO size was sufficient for use.

Pull the check out of the bufmgr, and actually check that the BO is
sufficiently-sized for our import one level up. This also resolves a
chicken/egg we have when importing bufers without explicit modifiers,
namely that we need the tiling mode to calculate the size, but we need
the BO imported to query the tiling mode.

Signed-off-by: Daniel Stone <daniels at collabora.com>
---
 src/mesa/drivers/dri/i965/brw_bufmgr.c   |  5 +----
 src/mesa/drivers/dri/i965/brw_bufmgr.h   |  2 +-
 src/mesa/drivers/dri/i965/intel_screen.c | 19 +++++++++++++++----
 3 files changed, 17 insertions(+), 9 deletions(-)

diff --git a/src/mesa/drivers/dri/i965/brw_bufmgr.c b/src/mesa/drivers/dri/i965/brw_bufmgr.c
index 2f17934700..b74fa9708b 100644
--- a/src/mesa/drivers/dri/i965/brw_bufmgr.c
+++ b/src/mesa/drivers/dri/i965/brw_bufmgr.c
@@ -1013,8 +1013,7 @@ brw_bo_get_tiling(struct brw_bo *bo, uint32_t *tiling_mode,
 }
 
 struct brw_bo *
-brw_bo_gem_create_from_prime(struct brw_bufmgr *bufmgr, int prime_fd,
-                             int size)
+brw_bo_gem_create_from_prime(struct brw_bufmgr *bufmgr, int prime_fd)
 {
    int ret;
    uint32_t handle;
@@ -1055,8 +1054,6 @@ brw_bo_gem_create_from_prime(struct brw_bufmgr *bufmgr, int prime_fd,
    ret = lseek(prime_fd, 0, SEEK_END);
    if (ret != -1)
       bo->size = ret;
-   else
-      bo->size = size;
 
    bo->bufmgr = bufmgr;
 
diff --git a/src/mesa/drivers/dri/i965/brw_bufmgr.h b/src/mesa/drivers/dri/i965/brw_bufmgr.h
index 56ec206d30..f708c30f05 100644
--- a/src/mesa/drivers/dri/i965/brw_bufmgr.h
+++ b/src/mesa/drivers/dri/i965/brw_bufmgr.h
@@ -272,7 +272,7 @@ void brw_destroy_hw_context(struct brw_bufmgr *bufmgr, uint32_t ctx_id);
 
 int brw_bo_gem_export_to_prime(struct brw_bo *bo, int *prime_fd);
 struct brw_bo *brw_bo_gem_create_from_prime(struct brw_bufmgr *bufmgr,
-                                            int prime_fd, int size);
+                                            int prime_fd);
 
 int brw_reg_read(struct brw_bufmgr *bufmgr, uint32_t offset,
                  uint64_t *result);
diff --git a/src/mesa/drivers/dri/i965/intel_screen.c b/src/mesa/drivers/dri/i965/intel_screen.c
index ceb1f0d480..65a60bfefe 100644
--- a/src/mesa/drivers/dri/i965/intel_screen.c
+++ b/src/mesa/drivers/dri/i965/intel_screen.c
@@ -845,6 +845,15 @@ intel_create_image_from_fds(__DRIscreen *dri_screen,
    image->pitch = strides[0];
 
    image->planar_format = f;
+
+   image->bo = brw_bo_gem_create_from_prime(screen->bufmgr, fds[0]);
+   if (image->bo == NULL) {
+      free(image);
+      return NULL;
+   }
+
+   image->modifier = tiling_to_modifier(image->bo->tiling_mode);
+
    int size = 0;
    for (i = 0; i < f->nplanes; i++) {
       index = f->planes[i].buffer_index;
@@ -857,13 +866,15 @@ intel_create_image_from_fds(__DRIscreen *dri_screen,
          size = end;
    }
 
-   image->bo = brw_bo_gem_create_from_prime(screen->bufmgr,
-                                                  fds[0], size);
-   if (image->bo == NULL) {
+   /* Check that the requested image actually fits within the BO. 'size'
+    * is already relative to the offsets, so we don't need to add that. */
+   if (image->bo->size == 0) {
+      image->bo->size = size;
+   } else if (size > image->bo->size) {
+      brw_bo_unreference(image->bo);
       free(image);
       return NULL;
    }
-   image->modifier = tiling_to_modifier(image->bo->tiling_mode);
 
    if (f->nplanes == 1) {
       image->offset = image->offsets[0];
-- 
2.13.0